The present invention relates to a developer supply container for supporting developer to an image forming apparatus of an electrophotographic type or the like and a stirring member usable therewithin, more particularly to a developer supply container for supplying a developer to an image forming apparatus such as a copying machine, a printer, a facsimile machine or the like and a stirring member usable therewith.
In a conventional image forming apparatus such as a copying machine and a printer of an electrostatic type or an electrophotographic type, fine particle toner it used as a developer. When the toner in the main assembly of image forming apparatus is consumed, the toner is supplied into the main assembly of image forming apparatus using a toner supply container.
Generally, the toner supply container comprises a main container body of a cylindrical or rectangular parallelepiped shape, made of synthetic resin material or the like, a sealing member for sealing an opening for supplying the toner from the main body on the container into the developing device, a stirring rotation member and a feeding member for stirring and feeding the toner from the inner portion toward the opening of the container. A process cartridge is used in which the toner supply container is integral with a photosensitive drum, a cleaner, a charger and the like, the process cartridge being situated in the main assembly of the image forming apparatus in use.
Since the toner are very fine particles, that is a problem that toner is scattered during the toner supplying operation, with a result of contamination of the operator or the surroundings of the container. In consideration of this problem, there has been proposed a system in which the toner supply container is situated in the image forming apparatus similarly to the process cartridge, and the toner is discharged through the opening thereof.
Such a stationary type toner supply container may be provided with a stirring rotation member to prevent caking of the toner and to deliver the toner. The stirring rotation member is driven or rotated through engagement between a main assembly side driver through a coupling member extended out of an end of the toner supply container or by direct engagement.
In such a toner supply container provided with a stirring rotation member, if a rotational stirring torque is large, a relatively expensive high-power electric motor is required, and it is necessary to raise the strength of the stirring rotation member.
Accordingly, various proposals have been made to reduce the rotational stirring torque. For example, Japanese Laid-open Patent Application Hei 8-272200 discloses a system in which a stirring rod of the stirring rotation member is rotatably supported by a spring, and when a load exceeding the elastic force of the spring acts on the stirring rod, the stirring rod flexes, by which the radius of rotation is shortened, and therefore, the rotational stirring torque is decreased. Japanese Laid-open Patent Application Hei 9-062072 discloses a system in which the rotational stirring torque is decreased by disposing three or more stirring blades of the stirring rotation member are disposed at the different angular positions.
However, such conventional systems involved the following problems. When the spring is need as with Japanese Laid-open Patent Application Hei 8-272200, the number of parts and number of assembling steps increase with the result of cost increase. When three or more stirring employees are disposed at different angular positions, the moldability and the assembling easiness property of the stirring blades are not good.
Therefore, there is a demand for a stirring rotation member in which the number of parts is a small, the moldability and the assembling easiness property are good, and the rotational stirring torque is small.
It is pointed out that if the strength of the stirring rotational member is made lower, the rotational stirring torque decreases because of the increased twisting flexibility of the rotational stirring blade, but the stirring effects also decreases with the result of remarkable increase of the bulk density after transportation of the toner supply container. It is desired that toner can be stably stirred with stability even in such a case.
Accordingly, it is a principal of officer of the present intention to provide a developer supply container with which the stirring torque can be reduced without deteriorating the strength of the stirring member. Accordingly, it is a principal object of the present invention to provide a stirring member with which the stirring torque can be reduced without deteriorating the strength of the stirring member.